Anode assembly for electrolytic aluminum and manufacturing method thereof

Abstract

The invention relates to the field of electrolytic aluminum, in particular to an anode assembly for electrolytic aluminum and a manufacturing method thereof. According to the invention, a plurality of layers of cross tables with first convex teeth are arranged on the upright post at the end part of the steel claw, a plurality of layers of second convex teeth are arranged around the inner wall of the carbon bowl, and the first convex teeth and the second convex teeth are staggered in the vertical direction, so that the contact area of the steel claw, the carbon bowl and phosphorus pig iron can be effectively increased, and good contact is always kept in the service period; and the voltage drop of the anode assembly is greatly reduced. In addition, rare earth elements such as La, Ce and Y, and components such as Cu, CaCO3 and CaC2 are introduced into the phosphorus pig iron, so that the flowability, the electrical conductivity and the thermal stability of the phosphorus pig iron are effectively improved, and the service life of the phosphorus pig iron is effectively prolonged. The anode assembly provided by the invention is simple in manufacturing method, low in voltage drop, good in thermal stability and stable in contact, and can effectively reduce the energy consumption of electrolytic aluminum production, improve the energy utilization rate and the production efficiency, save the cost and realize energy conservation and emission reduction.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrolytic aluminum, and in particular relates to an anode assembly for electrolytic aluminum and a manufacturing method thereof. Background Art

[0002] The production of electrolytic aluminum is a high-energy-consuming process. The greater the voltage drop, the higher the total voltage required to maintain the electrolytic reaction, which will lead to a significant increase in electricity consumption, thereby significantly increasing production costs. In addition, high voltage drop will reduce the energy efficiency of the entire electrolytic system. A large amount of electricity is consumed to overcome the voltage drop instead of being used for effective aluminum electrolysis reactions, resulting in a huge waste of energy. At the same time, excessive voltage drop may cause the actual effective voltage acting on the electrolytic cell to decrease, thereby slowing down the migration speed of aluminum ions and the speed of electrolysis reactions, which will extend production time, reduce aluminum production per unit time, and affect production capacity. Therefore, effectively reducing the voltage drop in the production process of electrolytic aluminum is of great significance in terms of energy conservation, emission reduction, cost reduction, and increased production capacity.

[0003] The anode assembly is an important component in aluminum electrolysis production and is also the main location where voltage drop occurs. It is composed of steel claws, phosphorus pig iron, and carbon anode. In the actual production process, due to the different thermal expansion coefficients of steel claws, phosphorus pig iron, and carbon anode, gaps are formed between the components, phosphorus pig iron has poor fluidity, and poor thermal stability during service leads to element loss. These reasons will cause a large voltage drop, resulting in high electrolysis energy consumption, extremely low energy efficiency, and inability to effectively improve production efficiency.

[0004] Based on this, an improved structure of an anode assembly for electrolytic aluminum and a method for manufacturing the same are provided, which can improve the fluidity and filling performance of phosphorus pig iron while promoting good contact between the components. This is of great significance for significantly reducing the pressure drop of the anode assembly, improving thermal stability and extending the service life of the anode assembly, and is also a technical problem that urgently needs to be solved. Summary of the invention

[0005] One of the purposes of the present invention is to provide an anode assembly for electrolytic aluminum that improves the filling performance of phosphorus pig iron, promotes good contact between various structures, significantly reduces voltage drop, and prolongs service life.

[0006] The second object of the present invention is to provide a method for manufacturing an anode assembly for electrolytic aluminum that improves the filling performance of phosphorus pig iron, promotes good contact between various structures, significantly reduces voltage drop, and extends service life.

[0007] The technical solution adopted by the present invention to achieve one of the purposes is: to provide an anode assembly for electrolytic aluminum, comprising: a steel claw, an anode carbon block and phosphorus pig iron; The end column of the steel claw is provided with a multi-layer cross platform, each layer of the cross platform includes four first protruding teeth arranged around the end column, and the first protruding teeth are provided with injection holes that pass through from top to bottom; The anode carbon block is provided with a plurality of carbon bowls, and the end columns of the steel claws are placed in the corresponding carbon bowls; the inner wall of the carbon bowl is provided with a plurality of second protruding teeth, and the second protruding teeth and the first protruding teeth are staggered in the vertical direction; The phosphorus pig iron is injected through the injection hole and the gap between the end column and the carbon bowl to fill the corresponding area, thereby achieving the connection between the steel claw and the anode carbon block.

[0008] The general idea of ​​an anode assembly for electrolytic aluminum provided by the present invention is as follows: In some existing solutions, the structure of the steel claw and the anode carbon block is usually improved to increase the contact area between the two, so as to reduce the pressure drop and save energy. However, the structural improvement of the steel claw and the anode carbon block also leads to the complication of the pouring channel structure. The phosphorus pig iron in the pouring process has the characteristics of high viscosity of molten metal. The high viscosity phosphorus pig iron flows in a complex pouring channel and is prone to defects such as pores and inclusions, which affects the integrity of the molding; in addition, the improved pouring channel structure also prolongs the pouring time, affecting production efficiency.

[0009] The anode assembly for electrolytic aluminum provided by the present invention increases the contact area between the steel claw and the anode carbon block by respectively setting a multi-layer cross platform with first protruding teeth on the end column of the steel claw, and setting a multi-layer second protruding teeth around the inner wall of the carbon bowl. The first protruding teeth and the second protruding teeth are staggered in the vertical direction to form a serrated casting channel, which cooperates with the casting of phosphorus pig iron, significantly increases the contact area between the steel claw and the anode carbon block, and ensures that the two are firmly connected and in good contact. On the other hand, considering the inconvenience caused by the complexity of the casting channel to the phosphorus pig iron casting process, the present invention opens a vertically through-through injection hole on each first protruding tooth of the cross platform. During the manufacturing process, the phosphorus pig iron is injected and filled in the corresponding area through the injection hole and the gap between the end column and the carbon bowl by a multi-region injection method, thereby reducing the flow area of ​​the molten phosphorus pig iron, thereby reducing defects such as pores and inclusions, improving the molding integrity, shortening the casting time, and improving production efficiency.

[0010] Furthermore, the present invention optimizes the formula of phosphorus pig iron on the basis of improving the structure of the steel claw and the anode carbon block to improve its fluidity and ensure the casting and connection quality.

[0011] In the present invention, the composition and content of the phosphorus pig iron are: C: 3.0wt.%-3.5wt.%; Si: 2.0 wt.%-2.5wt.%; Mn: 0.6 wt.%-0.9 wt.%; P: 0.5 wt.%-1.6 wt.%; S: 0.01wt.%-0.2wt.%; rare earth elements: 0.2wt.%-0.8 wt.%; Cu: 1 wt.%-3 wt.%; CaCO3: 1 wt.%-2 wt.%; CaC2: 1 wt.%-2 wt.%; and the rest is Fe.

[0012] Among the components of the above-mentioned phosphorus pig iron, rare earth elements can effectively reduce the pressure drop between the steel claw and the anode carbon block, greatly reduce energy consumption, and achieve the purpose of energy conservation and emission reduction; the addition of Cu can further reduce the pressure drop and improve the stability of phosphorus pig iron, and can also improve the high-temperature oxidation resistance and corrosion resistance of phosphorus pig iron, and extend the service life of phosphorus pig iron; the addition of CaC2 can effectively desulfurize, thereby increasing the fluidity of phosphorus pig iron, and avoid thermal cracking caused by excessive shrinkage of phosphorus pig iron, and improve the stability of phosphorus pig iron; the addition of CaCO3 can stir the molten phosphorus pig iron, increase the slag removal, prevent backsulfurization, and improve the slag removal effect of phosphorus pig iron, increase the fluidity of molten phosphorus pig iron, and promote the forming of phosphorus pig iron rings; the regulation of the five basic elements C, P, Si, Mn, and P can enable the phosphorus pig iron to maintain good strength, hardness, conductivity, fluidity and shrinkage during service.

[0013] Specifically, an appropriate amount of rare earth elements can form a conductive channel in phosphorus pig iron, increase carrier concentration, improve the bonding of phase boundaries, and reduce interface resistance, thereby improving the conductivity of phosphorus pig iron and reducing the voltage drop between the steel claw and the anode carbon block. However, excessive rare earth elements will cause a large amount of lattice distortion, increase the probability of electron scattering during movement, and reduce conductivity. Preferably, the content of rare earth elements is 0.2 wt.%-0.8 wt.%, and the rare earth elements are selected from at least one of La, Ce, and Y.

[0014] Cu has good electrical conductivity. When Cu is added to phosphorus pig iron, electrons are more easily conducted through copper phases or copper atoms, increasing the conductivity of phosphorus pig iron and reducing voltage drop. At the same time, an appropriate amount of Cu is mainly dissolved in ferrite, which not only causes lattice distortion, but also increases the bonding force between atoms, reduces the amplitude of atomic vibration, thereby reducing the thermal expansion coefficient of phosphorus pig iron and increasing stability. In addition, Cu can also improve the high temperature oxidation resistance and corrosion resistance of iron phosphide. However, excessive Cu will precipitate between crystals, causing the thermal expansion coefficient to increase and reducing the stability of phosphorus pig iron. Therefore, the present invention controls the content of Cu in phosphorus pig iron to be 1 wt.%-3 wt.%.

[0015] The main function of CaC2 is to desulfurize, thereby increasing the fluidity of phosphorus pig iron and preventing excessive shrinkage of phosphorus pig iron from causing thermal cracking. At the same time, it can achieve the effect of increasing carbon, improving the conductivity of phosphorus pig iron and reducing pressure drop. The reaction process is shown in formula (1).

[0016] (1) CaCO3 decomposes at high temperatures to produce CO2 and CaO. CO2 can stir the molten iron, thereby increasing the slag removal and preventing resulfurization. CaO can form a low-melting-point, high-fluidity CaSiO3 compound with slag SiO2, achieving a good slag removal effect, thereby increasing the fluidity of the molten iron. The reaction process is shown in formula (2) and formula (3).

[0017] (2) (3) Furthermore, the number of layers of the cross table is 2-4.

[0018] Furthermore, the longitudinal cross-sections of the first protruding tooth and the second protruding tooth are both trapezoidal.

[0019] Preferably, the height of the end columns is 100-130 mm; the width of the cross platform is 160-180 mm.

[0020] Preferably, the first protruding teeth have a tooth length of 50-60 mm, a tooth width of 45-55 mm, an inner tooth height of 28-32 mm, and an outer tooth height of 18-22 mm, wherein the inner tooth is the height of the first protruding teeth on the side connected to the end column, and the outer tooth is the height of the second protruding teeth away from the end column.

[0021] Preferably, the diameter of the injection hole is 25-35 mm. The injection hole provided in the first convex tooth can facilitate multi-channel injection of molten phosphorus pig iron, and can increase the contact area between the steel claw and the phosphorus pig iron and reduce the pressure drop.

[0022] Furthermore, the second protruding teeth surround the inner wall of the charcoal bowl and are distributed in layers; the number of layers of the second protruding teeth is the same as the number of layers of the cross platform of the end column.

[0023] Furthermore, each layer of the inner wall of the charcoal bowl is provided with 4-8 second protruding teeth at equal intervals.

[0024] Preferably, the depth of the charcoal bowl is 100-130mm; the tooth length of the second convex tooth is 18-22mm, the tooth width is 18-22mm, the inner tooth height is 25-35mm, and the outer tooth height is 18-22mm; wherein, the inner tooth is the height of the second convex tooth connected to the inner wall of the charcoal bowl, and the outer tooth is the height of the second convex tooth away from the inner wall of the charcoal bowl.

[0025] Preferably, in the carbon bowl, the diameter of the space enclosed by the outer teeth of the second convex teeth located in the same layer is 180-200 mm. Preferably, the diameter is 15-25 mm larger than the width of the cross table to facilitate the flow and filling of molten phosphorus pig iron.

[0026] In the present invention, the cross-sections of the first convex teeth and the second convex teeth are both trapezoidal structures. On the one hand, the first convex teeth of the trapezoidal structure of the multi-layer cross table cooperate with the second convex teeth of the carbon bowl to prevent the carbon block from falling off in unexpected situations; on the other hand, the staggered arrangement of multiple pairs of first convex teeth and second convex teeth of the trapezoidal structure can effectively increase the contact area between the steel claw and the phosphorus pig iron, increase the conductivity efficiency, and under the gravity of the carbon block, the steel claw can fit tightly with the phosphorus pig iron, eliminating the gap caused by the different thermal expansion coefficients of the materials, thereby reducing the pressure drop between the steel claw and the anode carbon block. In addition, the first convex teeth and the second convex teeth of the trapezoidal structure can also increase the bending moment resistance of the cross table and increase its service life.

[0027] The technical solution adopted by the present invention to achieve the second purpose is: to provide a method for manufacturing an anode assembly for electrolytic aluminum according to one of the purposes of the present invention, comprising the following steps: S1. pouring molten steel into steel claws with a cross platform at the end; S2, using rock tar as aggregate, coal tar as binder, and high temperature resistant brittle material as carbon bowl mold, after calcination, molding, and roasting, an anode carbon block with a plurality of carbon bowls is formed; S3, sand wash and remove rust on the cross table, and clean and dry the charcoal bowl; S4. Place the end column of the steel claw in the corresponding carbon bowl, pour molten phosphorus pig iron from the injection hole of the first convex tooth of the top cross platform and the gap between the end column and the carbon bowl to fill the corresponding area, so as to achieve the connection between the steel claw and the anode carbon block.

[0028] Furthermore, in step S2, the charcoal bowl mold is a sealed hollow mold; the high temperature resistant brittle material includes one of silicon nitride ceramics, alumina ceramics, quartz glass, and borosilicate glass.

[0029] Preferably, in step S2, after the anode carbon block is prepared, the high temperature resistant brittle material is broken into pieces to form a carbon bowl mold, thereby obtaining a carbon bowl with second convex teeth on the inner wall.

[0030] Furthermore, in step S2, the calcination temperature is 1200°C-1400°C. The main purpose of calcination is to remove volatile matter and moisture in the raw materials, improve the density, strength and conductivity of petroleum coke, and make the structure of petroleum coke more compact, so as to prepare for subsequent molding and roasting. Preferably, the roasting temperature is 1000-1300°C. The main purpose of roasting is to cause the coal tar pitch to undergo a coking reaction and form a coke structure, thereby improving the strength, conductivity and high temperature resistance of the anode.

[0031] Furthermore, in step S3, the main purpose of fully sandblasting and rust removal on the cross table is to remove metal oxides on the surface of the cross table to avoid affecting the conductivity between the steel claws and the phosphorus pig iron; the purpose of cleaning and drying the carbon bowl is to remove dust and moisture to avoid affecting the conductivity between the steel claws and the phosphorus pig iron.

[0032] Furthermore, in step S4, the pouring temperature of the phosphorus pig iron is 1200-1400° C. If the pouring temperature is too high, the phosphorus pig iron will shrink too much, causing the steel claws and the carbon block to loosen; while if the pouring temperature is too low, the molten phosphorus pig iron will have poor fluidity, reduced carburizing ability, and reduced conductivity.

[0033] Furthermore, in step S4, the pouring method of the molten phosphorus pig iron includes: pouring in each injection hole and gap in sequence in a manner surrounding the end column, or pouring in multiple channels (each injection hole and gap) at the same time.

[0034] Preferably, when pouring in each injection hole and gap in sequence by surrounding the end column, first pour a small amount of phosphorus pig iron in the 1# injection hole, then pour a small amount of phosphorus pig iron in the gap adjacent to the 1# injection hole in a clockwise or counterclockwise order, then pour a small amount of phosphorus pig iron in the 2# injection hole, and so on, until the phosphorus pig iron completely fills each corresponding area. Compared with the traditional single-area injection, this method allows the small amount of phosphorus pig iron injected first to be fully diffused in the corresponding channel, thereby improving the casting quality.

[0035] Preferably, when the pouring equipment can meet the needs of simultaneous multi-channel pouring, molten phosphorus pig iron is injected simultaneously into 8 channels including 4 injection holes and 4 gaps between the injection holes, which helps to quickly fill the phosphorus pig iron in the zigzag channels, improve the filling quality, and significantly improve production efficiency.

[0036] Compared with the prior art, the present invention has the following beneficial effects: The anode assembly for electrolytic aluminum provided by the present invention and its manufacturing method, on the one hand, a multi-layer cross table with first convex teeth is arranged on the end column of the steel claw, and a multi-layer second convex teeth is arranged around the inner wall of the carbon bowl, the first convex teeth and the second convex teeth are staggered in the vertical direction to form a serrated casting channel, which cooperates with the casting of phosphorus pig iron, significantly increases the contact area of ​​the steel claw, the anode carbon block and the phosphorus pig iron, ensures a firm connection and good contact, further reduces the pressure drop, and saves energy. On the other hand, the present invention opens an injection hole that passes through the top and bottom on each first convex tooth of the cross table. During the manufacturing process, the phosphorus pig iron is injected and filled in the corresponding area through the injection hole and the gap between the end column and the carbon bowl by a multi-area simultaneous injection method, thereby reducing the flow area of ​​the molten phosphorus pig iron, thereby reducing pores and inclusions, improving the molding integrity, shortening the casting time, and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of the structure of a steel claw provided in an embodiment of the present invention; Figure 2 A schematic diagram of the three-dimensional structure of a steel claw end column provided in an embodiment of the present invention; Figure 3 It is a cross-sectional schematic diagram of a cross platform provided with end columns in an embodiment of the present invention; Figure 4 is a cross-sectional schematic diagram of a charcoal bowl in an embodiment of the present invention; Figure 5 is a schematic cross-sectional structure diagram of an anode assembly in an embodiment of the present invention; Among them, 1-steel claw; 11-end column; 12-cross platform; 13-first convex tooth; 14-injection hole; 2-anode carbon block; 21-carbon bowl; 22-second convex tooth; 3-phosphorus pig iron. DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0039] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0040] The present invention provides an anode assembly for electrolytic aluminum, comprising: a steel claw 1, an anode carbon block 2 and phosphorus pig iron 3.

[0041] like Figure 1-3 As shown, the steel claw 1 has 4 columns, and the end column 11 is provided with a multi-layer cross platform 12, each layer of the cross platform 12 includes four first protruding teeth 13 arranged around the end column 11, and the first protruding teeth 13 are provided with an injection hole 14 that passes through from top to bottom. In the embodiment of the present invention, the diameter of the end column 11 is 70mm, and the height of the end column 11 is 100-130mm; the width of the cross platform 12 (the distance between the outer teeth of two opposite first protruding teeth 13) is 160-180mm, the number of layers of the cross platform 12 is 3, the tooth length of the first protruding teeth 13 is 50-60mm, the tooth width is 45-55mm, the inner tooth height is 28-32mm, the outer tooth height is 18-22mm, and the diameter of the injection hole 14 is 25-35mm.

[0042] The anode carbon block 2 is provided with a plurality of carbon bowls 21 for accommodating the end posts 11 of the steel claws 1. Figure 4As shown, the inner wall of the charcoal bowl 21 is provided with a plurality of second protruding teeth 22, and the second protruding teeth 22 and the first protruding teeth 13 are arranged alternately in the vertical direction. In the embodiment of the present invention, the second protruding teeth 22 surround the inner wall of the charcoal bowl 21 and are distributed in layers; the number of layers of the second protruding teeth 22 is the same as the number of layers of the cross platform 12 of the end column 11, both of which are 3 layers, and each layer of the inner wall of the charcoal bowl 21 is evenly spaced with 8 second protruding teeth 22. The depth of the charcoal bowl 21 is 100-130mm; the tooth length of the second protruding teeth 22 is 18-22mm, the tooth width is 18-22mm, the inner tooth height is 25-35mm, and the outer tooth height is 18-22mm; the diameter of the space enclosed by the outer teeth of the same layer is 180-200mm.

[0043] like Figure 5 As shown, phosphorus pig iron 3 is injected through the injection hole 14 and the gap between the end column 11 and the carbon bowl 21 and fills the corresponding area to achieve the connection between the steel claw 1 and the anode carbon block 2. The composition and content of the phosphorus pig iron used in the embodiment of the present invention are: C: 3.0wt.%-3.5wt.%; Si: 2.0 wt.%-2.5 wt.%; Mn: 0.6 wt.%-0.9 wt.%; P: 0.5 wt.%-1.6wt.%; S: 0.01wt.%-0.2wt.%; Rare earth elements: 0.2 wt.%-0.8 wt.%; Cu: 1 wt.%-3 wt.%; CaCO3: 1wt.%-2 wt.%; CaC2: 1 wt.%-2 wt.%; The rest is Fe. The rare earth element is selected from at least one of La, Ce, and Y.

[0044] The pouring temperature of phosphorus pig iron is 1200-1400° C. The molten phosphorus pig iron is poured in each injection hole 14 and the gap in sequence by surrounding the end column 11. First, a small amount of phosphorus pig iron is poured in the 1# injection hole, and then a small amount of phosphorus pig iron is poured in the gap adjacent to the 1# injection hole in a clockwise or counterclockwise order, and then a small amount of phosphorus pig iron is poured in the 2# injection hole, and so on, until the phosphorus pig iron completely fills each corresponding area.

[0045] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited thereto.

[0046] In Examples 1-3 of the present invention, the dimension data of the end column of the steel claw is shown in Table 1, the dimension data of the carbon bowl is shown in Table 2, and the composition and content (wt.%) of phosphorus pig iron is shown in Table 3.

[0047] Table 1

[0048] Table 2

[0049] Table 3

[0050] Example 1 This embodiment provides a method for manufacturing an anode assembly for electrolytic aluminum, comprising the following steps: Step 1: pouring molten steel into a steel claw 1 with a cross platform 11 at the end, the size data of the steel claw end column 11, the cross platform 12, the first protruding tooth 13 and the injection hole 14 are shown in Table 1; Step 2: using rock tar as aggregate, coal tar as binder, and high temperature resistant brittle material as carbon bowl mold, calcining and molding at 1300°C, and roasting at 1200°C to form an anode carbon block 2 with a plurality of carbon bowls 21, the size data of the carbon bowl 21 are shown in Table 2; wherein, the carbon bowl mold is a sealed hollow mold; and the high temperature resistant brittle material is quartz glass; Step 3: sand-wash and remove rust from the cross table 11, and clean and dry the charcoal bowl 21; Step 4: Place the end column 11 of the steel claw 1 in the corresponding carbon bowl 21, pour molten phosphorus pig iron 3 at 1250°C from the injection hole 14 of the cross table 12 and the gap between the end column 11 and the carbon bowl 21, fill the corresponding area, and realize the connection between the steel claw 1 and the anode carbon block 2. The composition and content of phosphorus pig iron are shown in Table 3, which has good fluidity and no obvious cracks after cooling.

[0051] Example 2 This embodiment provides a method for manufacturing an anode assembly for electrolytic aluminum, comprising the following steps: Step 1: pouring molten steel into a steel claw 1 with a cross platform 11 at the end, the size data of the steel claw end column 11, the cross platform 12, the first protruding tooth 13 and the injection hole 14 are shown in Table 1; Step 2: using rock tar as aggregate, coal tar as binder, and high temperature resistant brittle material as carbon bowl mold, calcining at 1200°C, forming, and roasting at 1100°C to form an anode carbon block 2 with a plurality of carbon bowls 21, the size data of the carbon bowl 21 are shown in Table 2; wherein, the carbon bowl mold is a sealed hollow mold; the high temperature resistant brittle material is silicon nitride ceramics; Step 3: sand-wash and remove rust from the cross table 11, and clean and dry the charcoal bowl 21; Step 4: Place the end column 11 of the steel claw 1 in the corresponding carbon bowl 21, pour molten phosphorus pig iron 3 at 1300°C from the injection hole 14 of the cross table 12 and the gap between the end column 11 and the carbon bowl 21, fill the corresponding area, and realize the connection between the steel claw 1 and the anode carbon block 2. The composition and content of phosphorus pig iron are shown in Table 3, which has good fluidity and no obvious cracks after cooling.

[0052] Example 3 This embodiment provides a method for manufacturing an anode assembly for electrolytic aluminum, comprising the following steps: Step 1: pouring molten steel into a steel claw 1 with a cross platform 11 at the end, the size data of the steel claw end column 11, the cross platform 12, the first protruding tooth 13 and the injection hole 14 are shown in Table 1; Step 2: using rock tar as aggregate, coal tar as binder, and high temperature resistant brittle material as carbon bowl mold, calcining at 1400°C, forming, and roasting at 1300°C to form an anode carbon block 2 with a plurality of carbon bowls 21, the size data of the carbon bowl 21 are shown in Table 2; wherein, the carbon bowl mold is a sealed hollow mold; the high temperature resistant brittle material is borosilicate glass; Step 3: sand-wash and remove rust from the cross table 11, and clean and dry the charcoal bowl 21; Step 4: Place the end column 11 of the steel claw 1 in the corresponding carbon bowl 21, pour molten phosphorus pig iron 3 at 1350°C from the injection hole 14 of the cross table 12 and the gap between the end column 11 and the carbon bowl 21 to fill the corresponding area, and realize the connection between the steel claw 1 and the anode carbon block 2. The composition and content of phosphorus pig iron are shown in Table 3, which has good fluidity and no obvious cracks after cooling.

[0053] Pressure drop comparison The steel claw was grinded 10 cm away from the rim of the bowl to remove the oxide film and then connected to one pole of a voltage-stabilized power supply. The carbon bowl was connected to the other pole of the voltage-stabilized power supply 10 cm away from the rim of the bowl and connected to a precision millivoltmeter. The voltage drop of the anode assembly for electrolytic aluminum prepared in Examples 1-3 was tested, and the anode assembly without the first convex tooth and the second convex tooth was used as the control group. The results after testing and calculation are shown in Table 4 below.

[0054] Table 4

[0055] As can be seen from the above table, The anode assembly for electrolytic aluminum provided by the present invention and the manufacturing method thereof, on the one hand, the first convex teeth and the second convex teeth are respectively arranged at the end of the steel claw and the inner wall of the carbon bowl to form a serrated casting channel, which increases the contact area between the end of the steel claw and the inner wall of the carbon bowl; on the other hand, Cu, rare earth elements, CaC2, and CaCO3 are added to the phosphorus pig iron, which improves the conductivity, slag removal, high temperature stability, and fluidity of the phosphorus pig iron, thereby further reducing the pressure drop and improving the molding effect of the phosphorus pig iron. The casting of the phosphorus pig iron significantly increases the contact area between the steel claw and the anode carbon block, ensuring that the two are firmly connected and in good contact. In the manufacturing process, the phosphorus pig iron is injected and filled in the corresponding area through the injection hole of the first convex tooth and the gap between the end column and the carbon bowl by a multi-region injection method, thereby reducing the flow area of ​​the molten phosphorus pig iron, thereby reducing pores and inclusions, improving the molding integrity, shortening the casting time, and improving the product quality. Compared with the conventional anode assembly connection structure, the anode assembly provided by the present invention can reduce the voltage drop value by 11.92%-12.80% under the same test conditions, thereby reducing production energy consumption and achieving the effect of saving energy.

[0056] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of the specification of the present invention should be included in the protection scope of the present invention.

Claims

1. An anode assembly for aluminum electrolysis, characterized in that: include: Steel claws (1), anode carbon blocks (2) and phosphorus pig iron (3); The end column (11) of the steel claw (1) is provided with a multi-layer cross platform (12), each layer of the cross platform (12) includes four first protruding teeth (13) arranged around the end column (11), and the first protruding teeth (13) are provided with injection holes (14) that penetrate up and down; The anode carbon block (2) is provided with a plurality of carbon bowls (21), and the end columns (11) of the steel claws (1) are placed in the corresponding carbon bowls (21); the inner wall of the carbon bowl (21) is provided with a plurality of second protruding teeth (22), and the second protruding teeth (22) and the first protruding teeth (13) are arranged alternately in the vertical direction; The phosphorus pig iron (3) is injected into and fills the corresponding area through the injection hole (14) and the gap between the end column (11) and the carbon bowl (21), thereby achieving connection between the steel claw (1) and the anode carbon block (2).

2. The anode assembly for aluminum electrolysis according to claim 1, characterized in that: The composition and content of the phosphorus pig iron (3) are: C: 3.0 wt.%-3.5 wt.%; Si: 2.0 wt.%-2.5 wt.%; Mn: 0.6 wt.%-0.9 wt.%; P: 0.5 wt.%-1.6 wt.%; S: 0.01 wt.%-0.2 wt.%; rare earth elements: 0.2 wt.%-0.8 wt.%; Cu: 1 wt.%-3 wt.%; CaCO3: 1 wt.%-2 wt.%; CaC2: 1 wt.%-2 wt.%; and the rest is Fe.

3. The anode assembly for aluminum electrolysis according to claim 1, characterized in that: The cross platform (12) has 2 to 4 layers.

4. The anode assembly for aluminum electrolysis according to claim 1, characterized in that: The longitudinal cross-sections of the first protruding tooth (13) and the second protruding tooth (22) are both trapezoidal.

5. The anode assembly for aluminum electrolysis according to claim 1, characterized in that: The second protruding teeth (22) surround the inner wall of the charcoal bowl (21) and are distributed in layers; the number of layers of the second protruding teeth (22) is the same as the number of layers of the cross platform (12) of the end column (11).

6. The anode assembly for aluminum electrolysis according to claim 5, characterized in that: Each layer of the inner wall of the charcoal bowl (21) is provided with 4 to 8 second protruding teeth (22) at equal intervals.

7. The anode assembly for aluminum electrolysis according to claim 5, characterized in that: The diameter of the space enclosed by the outer teeth of the second protruding teeth (22) located on the same layer is greater than the width of the cross platform (12).

8. The method for manufacturing an anode assembly for electrolytic aluminum according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, pouring molten steel into a steel claw (1) with a cross platform (11) at the end; S2, using rock tar as aggregate, coal tar as binder, and high temperature resistant brittle material as carbon bowl mold, and forming an anode carbon block (2) with a plurality of carbon bowls (21) after calcination, molding, and roasting; S3, sand washing and rust removal of the cross table (11), and dust removal and drying of the charcoal bowl (21); S4. Place the end column (11) of the steel claw (1) in the corresponding carbon bowl (21), pour molten phosphorus pig iron (3) from the injection hole (14) of the first protruding tooth (13) of the top cross platform (12) and the gap between the end column (11) and the carbon bowl (21) to fill the corresponding area, thereby achieving the connection between the steel claw (1) and the anode carbon block (2).

9. The manufacturing method according to claim 8, characterized in that: In step S2, the charcoal bowl mold is a sealed hollow mold; the high temperature resistant brittle material includes one of silicon nitride ceramics, alumina ceramics, quartz glass, and borosilicate glass.

10. The manufacturing method according to claim 8, characterized in that: In step S4, the pouring temperature of the phosphorus pig iron (3) is 1200-1400°C.

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